This section describes the approaches and methods that will be used to compare the immunogenicity of vaccine constructs developed in Projects 1-4 )i.e., synthetic peptide-liposome, recombinant proteins, recombinant vaccinia, and BCG). The methods for identification of important epitopes (B, Th and Tc, as well as various combinations of these) found on HIV gene products are outlines. These include the use of ELISA and virus neutralization assays for monitoring antibody responses, and T cell proliferation, cytotoxic T lymphocyte (CTL), and antibody dependent cellular cytotoxicity (ADCC) assays for monitoring CMI responses. Most of the proposed work will be carried out using congenic mice of several haplotypes, but human sea and cells will also be used to verify data derived using the mouse model.